Which of the following is a technique to achieve the illuson of forms projecting into space

There are many techniques that people make to become morespiritually enlightened. Some of these are meditation, prayer,chanting, yoga, martial arts, fasting, dancing and psychedelics.

What i think is that it adds loudness for preachers/church choirs. it is also able to hold up a lot of weight without pillars. : )) idek tho

Hey can you attach the piece or let me know the name of it?